NEUROPHYSIOLOGIC AND BEHAVIORAL MEASURES OF PHONETIC

NEUROPHYSIOLOGIC AND BEHAVIORAL MEASURES OF PHONETIC

PERCEPTION IN ADULT SECOND LANGUAGE

SPEAKERS OF SPANISH

by

Jaden Hellewell

A thesis submitted to the faculty of

Brigham Young University

in partial fulfillment of the requirements for the degree of

Master of Science

Department Communication Disorders

Brigham Young University

April 2007

BRIGHAM YOUNG UNIVERSITY

GRADUATE COMMITTEE APPROVAL

of a thesis submitted by

Jaden Hellewell

This thesis has been read by each member of the following graduate committee and by majority vote has been found to be satisfactory. Date David L. McPherson, Chair Date Shawn Nissen Date Christopher Dromey

BRIGHAM YOUNG UNIVERSITY

As chair of the candidate’s graduate committee, I have read the thesis of Jaden Hellewell in its final form and have found that (1) its format, citations, and bibliographical style are consistent and acceptable and fulfill university and department style requirements; (2) its illustrative materials including figures, tables, and charts are in place; and (3) the final manuscript is satisfactory to the graduate committee and is ready for submission to the university library. Date David L. McPherson Chair, Graduate Committee Accepted for the Department Ron W. Channell Graduate Coordinator Accepted for the College K. Richard Young Dean, David O. McKay School of Education

ABSTRACT

NEUROPHYSIOLOGIC AND BEHAVIORAL MEASURES OF PHONETIC

PERCEPTION IN ADULT SECOND LANGUAGE

SPEAKERS OF SPANISH

Jaden Hellewell

Department of Communication Disorders

Master of Science

Infants 6-8 months old are able to identify nearly every speech sound contrast on

which they have been tested, regardless of whether that contrast represents an across-

category (two different phonemes) phonetic change in their native language or not. A

child’s ability to identify non-native consonant contrasts greatly diminishes by 11-12

months of age. The present study examined speech sound discrimination in three groups

of listeners. Adult second language (L2) listeners of Spanish were compared with native

English listeners with no knowledge of Spanish and native Mexican listeners to

determine if they would show the ability to discriminate phonetic distinctions that are

present in Spanish and not English. Behavioral and Electrophysiological measures were

obtained in response to a continuum of bilabial consonant-vowel (CV) stimuli that

differed in voice onset time (VOT) from -50 to 30 ms VOT (/ba/ to /pa/). The -50 ms

VOT stimulus was paired with each of the others to form stimulus pairs with varying

degrees of acoustic difference. Behavioral data showed that L2 listeners of Spanish

perceived a transition from /ba/ to /pa/ later than native Spanish listeners but earlier than

English only listeners. Electrophysiological data using the mismatch negativity revealed

that the both L2 Spanish and native Spanish listeners perceived a distinction between

stimuli in the stimulus pairs 20 ms earlier than English only listeners. These results

support the theory that underlying neural-sensory representations of speech may be

altered by linguistic experiences, and that the loss of non-native speech sound

discrimination abilities in infancy and the regaining of these abilities in adulthood is not

due merely to attentional bias.

ACKNOWLEDGMENTS

Many hours of work went into this project and not all of them were mine. I want

to thank my thesis committee chair Dr. David McPherson for his dedicated help and

teaching. I would also like to thank the other members of my committee Dr. Shawn

Nissen and Dr. Christopher Dromey. Thank you to my many participants many others

who gave me advice and help throughout the process. I am especially grateful to my

loving wife, Kira, for her constant encouragement and unwavering support.

vii

TABLE OF CONTENTS

Page

List of Tables ..................................................................................................................... ix

List of Figures ..................................................................................................................... x

List of Appendixes ............................................................................................................ xii

Literature Review................................................................................................................ 1

Developmental Speech-Sound Perception .............................................................. 1

The Mismatch Negativity ....................................................................................... 4

The Mismatch Negativity and Speech-Sound Discrimination ................................ 7

The Mismatch Negativity and Second Language Learning .................................... 8

Method .............................................................................................................................. 11

Participants ............................................................................................................ 11

Stimuli ................................................................................................................... 11

Procedures for Behavioral Experiment ................................................................. 14

Procedures for Electrophysiological Experiment ................................................. 14

Data Analysis ........................................................................................................ 15

Results ............................................................................................................................... 16

Behavioral Results ................................................................................................ 16

MMN Results ........................................................................................................ 16

Scalp Distribution Within Groups ........................................................................ 21

Scalp Distribution Across Groups ........................................................................ 49

Statistical Analysis ................................................................................................ 54

Discussion ......................................................................................................................... 55

References ......................................................................................................................... 59

viii

Appendixes ....................................................................................................................... 64

ix

LIST OF TABLES

Table Page

1. Descriptive Statistics for Average Peak Latencies (Plat) of the MMN ........................ 19

2. Descriptive Statistics for Average Peak Amplitudes (Pamp) of the MMN .................. 20

3. Descriptive Statistics for RMS Amplitudes of the MMN at the CPZ Electrode .......... 22

x

LIST OF FIGURES

Figure Page

1. Waveforms representing the eight stimuli used in the experiment ............................. 13

2. Mean identification functions for the /bɑ/-/pɑ/ continuum for each group are

represented in Figures 2A-2C. Figure D shows all three groups................................17

3. Graphs representing presence or absence of MMN in each group at each stimulus . 18

4. Scalp distribution map for group 1 -40 ms VOT......................................................... 23

5. Scalp distribution map for group 1 -30 ms VOT .........................................................24 6. Scalp distribution map for group 1 -20 ms VOT......................................................... 25

7. Scalp distribution map for group 1 -10 ms VOT .........................................................27 8. Scalp distribution map for group 1 0 ms VOT …........................................................ 28 9. Scalp distribution map for group 1 10 ms VOT .......................................................... 29 10. Scalp distribution map for group 1 20 ms VOT ......................................................... 30

11. Scalp distribution map for group 1 30 ms VOT .......................................................... 31 12. Scalp distribution map for group 2 -40 ms VOT .........................................................33 13. Scalp distribution map for group 2 -30 ms VOT .........................................................34 14. Scalp distribution map for group 2 -20 ms VOT ........................................................ 35

15. Scalp distribution map for group 2 -10 ms VOT .........................................................36 16. Scalp distribution map for group 2 0 ms VOT …........................................................ 38 17. Scalp distribution map for group 2 10 ms VOT .......................................................... 39 18. Scalp distribution map for group 2 20 ms VOT .......................................................... 40 19. Scalp distribution map for group 2 30 ms VOT .......................................................... 38

20. Scalp distribution map for group 3 -40 ms VOT .........................................................42

xi

21. Scalp distribution map for group 3 -30 ms VOT .........................................................43 22. Scalp distribution map for group 3 -20 ms VOT .........................................................45 23. Scalp distribution map for group 3 -10 ms VOT .........................................................46 24. Scalp distribution map for group 3 0 ms VOT ............................................................ 47 25. Scalp distribution map for group 3 10 ms VOT .......................................................... 48 26. Scalp distribution map for group 3 20 ms VOT .......................................................... 50 27. Scalp distribution map for group 3 30 ms VOT .......................................................... 51

xii

LIST OF APPENDIXES

Appendix Page

A. Informed Consent Document ...................................................................................... 64

B. Words Used for Stimulus Recordings ......................................................................... 66

C. List of Sentences Read by Speaker ............................................................................. 67

D. Tables of RMS Amplitudes......................................................................................... 69

1

Literature Review

Little is known about the neurological processes involved in speech sound

perception and second language (L2) learning. A few recent studies have begun to

explore this topic directly, and have dealt mainly with the perception of non-native

vowels (Nenonen, Shestakova, Huotilainen, & Naatanen, 2005; Shestakova, Huotilainen,

Ceponiene, & Cheour, 2003; Winkler & Kujala et al., 1999). The exploration of this topic

began with studies devoted to developmental language learning and speech sound

perception.

Developmental Speech-Sound Perception

A significant body of research has shown that infants 6-8 months old are able to

identify nearly every speech sound contrast on which they have been tested, regardless of

whether that contrast represents an across-category (AC, two different phonemes)

phonetic change in their native language or not. Infants can identify contrasts that form a

within-category (WC, same phoneme) phonetic change in their native language and an

AC phonetic change in another language, to which the infant has not been exposed. The

research has also shown that a child’s ability to identify non-native consonant contrasts

greatly diminishes by 11-12 months (Werker, 1991). Research by Best, McRoberts, and

Sithole (1988) comparing Zulu click contrasts in English speaking adults and infants

provided a caveat to this theory. They concluded that if the nonnative contrasts are not

likely to be assimilated into any native phonemic category (such as a Hindi retroflex /ɖɑ/

being perceived by English speakers as dental /dɑ/), the ability to discriminate the sounds

will continue into adulthood because perception will focus on purely auditory or phonetic

properties.

2

A study by Werker, Gilbert, Humphrey, and Tees (1981) used 6-8 month old

infants, native Hindi speakers, and native English speakers to test consonant contrasts

that are present in Hindi, but not in English. The first Hindi consonant contrast involved a

change in place of articulation, a voiceless dental stop verses voiceless retroflex stop. The

second involved a contrast between a voiceless aspirated stop and a breathy voiced dental

stop, in which a change in voice onset time (VOT) is the main distinction. The study

found that the 6 month old infants were able to discriminate both Hindi sound pairs along

with the native Hindi speaking adults. The native English speaking adults, however, were

not able to distinguish the place of articulation contrast, and only some were able to

distinguish the VOT contrast.

The early age at which children lose this discrimination ability was shown by

Werker and Lalonde (1988), who tested discrimination abilities in native Hindi speaking

adults, native English speaking adults, 6-8 month old English-learning infants, and 11-13

month old English-learning infants. The stimuli used were two phoneme pairs with

varying VOT. The first represented a phonetic change common to both languages, and

the second represented a change only in Hindi. The researchers found that the younger

infants were able to discriminate both the contrast common to both languages and the

contrast found only in Hindi, while the older infants and the native English speakers were

only able to discriminate the common contrast.

Further research has helped describe the development of vowel discrimination.

Polka and Werker (1994) tested the discrimination of two German vowel contrasts in

English-learning infants of 6-8 months and 10-12 months of age. This study showed, as

expected, that the 6-8 month old infants were able to distinguish the German vowels with

3

more accuracy than the 10-12 month old infants. The difference between the two groups

was not as significant as expected, however. The researchers then tested another, younger

group of infants (four months old) on the same stimuli. The four month old infants

showed improved discrimination beyond that of the 6-8 month old group. The researchers

concluded that there is a developmental shift from a general phoneme recognition pattern

to language-specific phoneme recognition pattern within the first year of life, as shown

by previous consonant discrimination studies, but they also concluded that this change

appears to begin earlier for vowels than it does for consonants. Additionally, research by

Kuhl, Williams, Lacerda, Stevens, and Lindblom (1992) used the “perceptual magnet

affect” to show that at six months of age English and Swedish speaking infants’ vowel

perception was already influenced by the language to which they were exposed. Both

groups of infants showed a stronger magnet effect for their own native language

prototype vowel than for the other languages prototype vowel.

Evidence from these studies suggest the inability of adults and children to

distinguish nonnative speech sounds. Because of the ability that adults and children have

to relearn how to discriminate nonnative contrasts when learning a new language, the

prevailing theory has been that this loss of speech sound discrimination is due to

attentional bias rather than neural-sensory loss (Pisoni, Lively, & Logan, 1994; Werker,

1994). More recent studies (Dehaene-Lambertz, 1997; Sharma & Dorman, 1999) using

electrical brain responses, specifically the auditory evoked potential (AEP), have

investigated the underlying neural-sensory representations of speech to determine if they

are actually altered by linguistic experiences.

4

The Mismatch Negativity

The mismatch negativity (MMN) is commonly used in AEP studies of speech

sound discrimination. The MMN is a negative component of the AEP elicited by a

physically deviant stimulus following a series of homogeneous, or standard, stimuli, and

generally occurs between 100 and 200 ms after change onset (Naatanen, Gaillard, &

Mantysalo, 1978). The MMN is specific to auditory stimuli (Nyman et al., 1990) and is

currently the only valid objective measure of central auditory processing accuracy in the

brain. The MMN is best recorded when the subject’s attention is directed away from the

auditory stimulation (Naatanen & Escera, 2000) because processes underlying the MMN

are automatic and pre-attentive (Aaltonen, Niemi, Nyrke, & Tuhkanen, 1987). In other

words, the process takes place before conscious attention is paid to the auditory

stimulation.

Repeated exposure to a given auditory stimulus creates a memory trace in the

brain which accurately represents the stimulus features. The memory trace can be created

after only a few repetitions. When the deviant stimulus is presented, it is compared with

the previously formed memory trace. If a mismatch is present in the comparison of the

deviant stimulus and the memory trace, the MMN is elicited (Cheour et al., 1998;

Naatanen & Escera, 2000; Naatanen, Jiang, Lavikainen, Reinikainen, & Paavilainen,

1993; Naatanen, Schroger, Karakas, Tervaniemi, & Paavilainen, 1993). The MMN is

elicited, not only by changes in the acoustic signal itself, but also by changes to the silent

intervals between stimuli, or the inter-stimulus interval (Naatanen & Jiang et al., 1993).

Long term neural learning effects can be found with continued presentation of unfamiliar

stimuli; however, long term adaptive changes require attention and effort (Naatanen and

5

Schroger et al., 1993).

The MMN tolerates some variation in the standard stimuli. Winkler et al. (1990)

demonstrated that slight changes in frequency and intensity in the standard stimuli affect

the amplitude (μV) and area (μV × ms) of the MMN response but do not eliminate it. The

amplitude and area decrease with increased variation of the standard stimuli (Winkler et

al., 1990). The amplitude of the MMN also varies as a function of the magnitude of

change between the deviant stimulus and the standard stimuli. As the difference between

the standard and the deviant stimuli increases, the amplitude of the MMN also increases

(Jaramillo, Paavilainen, & Naatanen, 2000; Savela et al., 2003).

The MMN has been elicited by a range of stimulus variations including changes if

phonetic structure such as frequency, intensity, spatial locus of origin, rise time, and

duration (Naatanen, 1992). The MMN has also been elicited by changes in natural and

synthetic speech sounds (Aaltonen et al., 1987; Savela et al., 2003; Sharma, Kraus,

McGee, Carrell, & Nicol, 1993; Winkler & Lehtokoski et al., 1999). There is some

disagreement as to whether the MMN reflects processing of only the acoustic aspects of

speech or whether it also reflects phonetic processing into categories. Sharma et al.

(1993) compared the MMN elicited by two stimulus pairs across the /dɑ/ - /ɖɑ/

continuum. They found that a WC pair, where both phonemes were perceived as /dɑ/,

and an AC pair, where one phoneme was perceived as /dɑ/ and the other as /ɖɑ/, both

elicited equal MMN responses. The MMN did not differ in latency (onset, peak and

offset), amplitude, or area and the acoustic difference (starting F2 and F3 frequencies)

between the two pairs of stimuli were equivalent. The authors therefore concluded that

the MMN reflects the processing of only acoustic aspects of speech. Another study by

6

Savela et al. (2003) used Finnish subjects to compare native vowels with non-native

vowels (a Finnish vowel was paired with a Komi vowel) in an electrophysiological

experiment, measuring the MMN, and a behavioral experiment, measuring the reaction

time for identification of the deviant vowel. They used three stimulus pairs with varying

amounts of acoustic difference between them. They found that in one stimulus pair, /e-ε/,

the reaction time was longer when the Komi vowel /ε/ was the standard stimulus than

when the Finnish vowel /e/ was the standard stimulus. The same pattern was not found

with regard to the MMN. They concluded that the phonemic status of the standard

stimulus only plays a role at the attentive level, not the pre-attentive level.

Winkler and Lehtokoski et al. (1999) found that the pre-attentive change-

detection process generating the MMN utilizes both auditory and phonetic

representations. They used Hungarian and Finnish speaking subjects, and tested them

with two vowel stimulus pairs. One pair represented an AC change in Hungarian and a

WC change in Finnish, while the other pair represented an AC change in Finnish and a

WC change in Hungarian. The MMN data that they collected showed a larger amplitude

in AC contrasts than in WC contrasts in both language groups. Based on this evidence,

the researchers concluded that there is both auditory and phonetic involvement in

generation of the MMN.

The MMN can be used to delineate the stages of auditory information processing

in the same way as behavioral responses. However, MMN experiments provide more

accurate and specific information about the emergence of auditory stimulation

representations than do behavioral experiments. The pre-attentive nature of the MMN

protects it from contamination by voluntary processes. Although the MMN reflects pre-

7

attentive auditory perception, the absence of the MMN does not rule out behavioral

discrimination. For this reason, it is imperative that sound discrimination experiments

done using the MMN are accompanied by behavioral experiments (Naatanen & Winkler,

1999).

The Mismatch Negativity and Speech-Sound Discrimination

Many experiments have used the MMN to study speech sound discrimination in

children and adults because of the accuracy and specificity of the information obtained by

using the MMN. A study by Dehaene-Lambertz (1997), one of the earliest to use MMN

data to study speech sound discrimination, used changes in place and manner of

articulation to elicit the MMN; the stimuli were similar to those used by Werker and

Lalonde (1988). The stimulus set represented two different phonemes for the French

subjects (/bɑ/ and /dɑ/) while native Hindi speakers distinguished three phonemes (/bɑ/,

dental /dɑ/, and retroflex /ɖɑ/). Behavioral data for French subjects corresponded with

MMN results which showed an ability to discriminate the native contrasting sounds, but

not the nonnative contrast. The MMN was significantly stronger in the French subjects

when the stimulus represented an AC phonetic change in French, than when it

represented an AC phonetic change in Hindi and a WC phonetic change in French. The

authors concluded that the subjects’ inability to discriminate non-native phonetic

contrasts does not seem related to attention bias, but rather to a loss of auditory

discrimination abilities.

Other studies have contrasted different types of phonetic boundaries.

Discrimination of VOT changes in a /dɑ/-/tɑ/ continuum in English (/dɑ/ and /tɑ/ are

primarily distinguished by VOT) measured using behavioral and electrophysiological

8

methods, showed that the MMN evoked by an AC change were much stronger than those

evoked by a WC change for native English speakers. The behavioral identification of the

VOT changes coincided with the MMN data (Sharma & Dorman, 1999). A later study

contrasted English and Hindi listeners’ perception of VOT changes across a /bɑ/-/pɑ/

continuum. They found that when the stimuli changes presented were phonetically

significant to native Hindi listeners but not native English listeners, a significantly larger

MMN was evoked in the Hindi listeners. Again, a behavioral experiment showed

perceptual boundaries coincided with the boundaries revealed by the MMN. All of the

syllables presented were pre-voiced, therefore, English listeners perceived only /bɑ/,

while Hindi speakers perceived differences between /bɑ/ and /pɑ/ depending on the

amount of pre-voicing (Sharma & Dorman, 2000).

The Mismatch Negativity and Second Language Learning

Electrophysiological data have also supplied valuable information about brain

function when an L2 is learned after the first year of life; which may be after the ability to

distinguish nonnative sounds has been lost. Winkler and Kujala et al. (1999) used the

MMN to measure electrophysiological responses to native and nonnative vowel contrasts

in native Hungarian speakers who are fluent L2 Finnish speakers. The researchers

contrasted a group of native Hungarians fluent in Finnish with a group of native

Hungarians with no exposure to Finnish and a native Finnish group. A vowel contrast

that is found only in Finnish was compared to a vowel contrast that is present in both

languages. The MMN was elicited in both the native Finnish and fluent Hungarian

subjects when presented with the Finnish-only vowel contrast, but it was not elicited in

the Hungarians with no knowledge of Finnish. The MMN was elicited in all three subject

9

groups when the vowel contrast common to both languages was presented. These results

coincided with perceptual abilities of the three groups in the behavioral portion of the

study. When the Finnish-only vowels were presented, the Finns identified them with 90%

accuracy and the Finnish-fluent Hungarians identified them with 80% accuracy, while the

Finnish-naïve Hungarians identified the vowels at a chance level. The fact that the MMN

was present in the fluent Hungarians as well as the native Finns, and not the naïve

Hungarians shows evidence of L2 learning at a neural-sensory level.

The ability to perceive nonnative vowel contrasts, as shown by

electrophysiological data, was also demonstrated by Finnish children (3 to 6 years old)

learning French. A group of Finnish children enrolled in a French school was compared

to a group of Finnish children enrolled in Finnish-only schools and daycares. They were

presented with contrasting French vowels that do not correspond closely to Finnish

vowels. The MMN elicited in the French-learning group was significantly larger than

MMN elicited in the Finnish-only group after only 3 to 4 months of enrollment in the

French schools. This study again shows evidence of L2 learning at a neural-sensory level.

Overall, however, the body of research relating to AEPs and L2 learning is still relatively

small (Shestakova et al., 2003).

In several of the above studies the Hindi language has been compared to English

because of the differences in VOT between English and Hindi stops. Sharma and Dorman

(2000), for example, found that Hindi listeners identified bilabial plosive phonemes with

VOTs of 0 and -20 ms as /p/, and bilabial phonemes with VOTs of -50 and -90 ms as /b/.

The English listeners, however, perceived all four phonemes as /b/. Research findings

have indicated that English listeners do not consistently perceive /p/ until the VOT

10

reaches 25 ms or more (Lisker & Abramson, 1970). A comparison between English and

Spanish shows a similar phenomenon. While in English /b/ is produced with a VOT of

approximately 0 ms and /p/ is produced with a VOT of 50 ms or more, in Spanish /b/ is

pre-voiced with a VOT of less than -50 ms and /p/ is produced with a VOT of

approximately 0 ms (Lisker & Abramson, 1964). Based on this VOT data it is expected

that English listeners would perceive Spanish /b/ and /p/ only as /b/. Voice onset times for

bilabial stops have been shown to differ somewhat in different Spanish dialects.

However, all the Spanish dialects tested show similar differences from English VOTs

(Rosner, Lopez-Bascuas, Garcia-Albea, & Fahey, 2000).

The current study addresses the issue of the MMN in L2 learners as it relates to

VOT. More evidence is needed to know if speech-sound discrimination abilities that are

lost after infancy can be relearned in adulthood at a neural-sensory level as shown by the

MMN, particularly in consonant sound pairs. As stated above, the review by Pisoni,

Lively, and Logan (1994) points out that people have the ability to relearn nonnative

phonetic contrasts; therefore, it is also expected that as a native English speaker learns

Spanish, the speaker will learn to distinguish the Spanish phonemes of /b/ and /p/

according to common Spanish VOTs. The current study was designed to test this

hypothesis behaviorally and electrophysiologically, to find out whether behavioral

responses and the MMN evoked by changes in VOT in L2 adult speakers of Spanish

resemble the MMN of native Spanish speakers when the stimuli represent an AC change

in Spanish, but a WC change in English.

11

Method

Participants

Thirty adult listeners between the ages of 18 and 35 took part in this study.

Participants were divided into 3 groups. The first group of participants consisted of 10

native English listeners with no knowledge of Spanish. The second group of participants

consisted of 10 native Mexican listeners who spent at least the first 17 years of their life

in their native country. The third group of participants consisted of 10 native English

listeners who have learned Spanish as a second language in adulthood and had recently

(within 18 months of return) spent 20-24 months in Mexico. All participants

demonstrated normal hearing with pure-tone thresholds of ≤ 15 dB HL at 250, 500, 1000,

2000, and 4000 Hz bilaterally (American National Standards Institute [ANSI], 1996), and

displayed normal, type A, tympanograms (Martin & Clark, 2005). No participant had a

recent (within 60 days) respiratory infection or reported history of neuropsychiatric

disorders or head trauma.

Stimuli

A female native Mexican speaker who lived in Mexico until at least age 17 served

as talker for the recording of the stimuli. The speaker was recorded while saying the list

of Spanish sentences found in Appendix C. Each sentence contained a Spanish bisyllabic

word beginning with /bɑ/ or /pɑ/. Each sentence was used five times and the order was

randomized. The list of words is found in Appendix B. The sentences were recorded

online to a computer in a sound isolated chamber. A low-impedance dynamic

microphone (DPA 4011) and an analog/digital converter (Apogee Mini-me) were used to

record the participant’s productions. The microphone was affixed to a microphone stand

12

and placed approximately 6 inches from the speaker’s lips during recording. The speech

tokens were sampled at 96 kHz and low-pass filtered at 22.05 kHz with 24 bit

quantization.

The experimental stimuli consisted of a continuum of 9 stimulus tokens (T1-T9)

differing in terms of voice onset time (-50 ms to +30 ms VOT). Each syllable differed by

10 ms. The initial token in the stimulus continuum (T1 or -50 ms VOT) is commonly

perceived by both English and Spanish listeners as /bɑ/ while the terminal token (+30 ms

VOT) is often perceived as /pɑ/. The experimental stimuli were created using Adobe

Audition (2003). The initial /bɑ/ from the word “banda” was chosen because the pre-

voicing segment was regular and represented average Spanish VOTs. The initial /bɑ/ was

extracted from the word and the final 3 ms of the vowel were ramped to eliminate noise

from the segment. The pre-voicing segment of the /b/, which was originally 80 ms long,

was cut to 50 ms for the first sample. The pre-voicing was cut to 40 ms for the second

sample, 30 ms for the third, 20 ms for the fourth, 10 ms for the fifth, and the pre-voicing

was cut completely for the sixth. To create the positive VOT syllables, the /p/ burst from

the word “panda” was cut at a zero crossing of the waveform and added in the place of

the 50 ms pre-voicing segment of the first token, which was also cut at zero crossings.

This was done to achieve a naturalistic burst while keeping a consistent subsequent vowel

nucleus for all continuum tokens. The original /p/ burst was 10 ms long. Small portions

of that burst were copied and added in again to create the +20 and +30 ms VOT syllables.

The vowel portions of the burst syllables were also ramped during the final 3 ms so that

all samples had the exact same vowel. Waveforms for the 9 stimuli used are found in

Figure 1.

13

Figure 1. Waveforms representing the nine stimuli used in the experiment.

14

Procedures for Behavioral Experiment

Following the tympanograms and hearing screenings, the participants were seated

in a comfortable recliner in a sound-isolated chamber. The stimuli were presented

through insert phones with an intensity of 70 dB HL. The participants used a push button

controller with buttons labeled “ba” and “pa”. They were instructed to push the button

corresponding to the syllable they heard. The participants were presented with two trials

of 180 syllables. Each syllable was presented 20 times per trial. No training was given

prior to the start of the experiment.

Procedures for Electrophysiological Experiment

The participants were again seated in a comfortable recliner in a sound-isolated

chamber. The stimuli were presented through insert phones with an intensity of 70 dB

HL. The participants brought a book of their choosing and were instructed to stay alert

and read while the sounds were presented to them. They were told to ignore the stimuli.

The MMN was obtained by presenting a “common” or “standard” stimulus in contrast to

a second “deviant” stimulus with a stepped variation from the first stimulus token. The -

50 ms VOT /bɑ/ token was used as the standard and was paired with each of the other 8

tokens to form the stimulus pairs. Each paired comparison was presented with 480 trials.

The common syllable occurred 399 times (83%), and the deviant syllable occurred 81

times (17%). The participants were fitted with a NeuroScan 32-electrode cap. Each

electrode was filled with ECI Electro-gel to reduce impedance to 10 kOhms or less. A

NeuroScan computer using Scan 4.2 software was used to collect and analyze the AEP

waveforms. Raw electrical potentials were bandpassed from 0.05 to 70 Hz.

15

Data Analysis

The AEP waveforms obtained for each participant were averaged for both the

standard and the deviant conditions and analyzed. Grand averages were also computed

across subjects in the standard and deviant conditions and analyzed. Since the MMN is a

potential elicited by the deviant stimulus in a deviant paradigm, amplitude, area, and

latency of the MMN were measured from a difference wave computed by subtracting the

deviant response from the standard response. Difference waveforms were computed on

each set of standard and deviant condition waveforms for each participant, as well as for

the grand average waveforms.

The latency of the MMN was measured at the peak (point of maximum

negativity) as well as at the onset (beginning) and the offset (end) points of the MMN

component of the difference waveform. The MMN peak was defined as the prominent

negative peak within the latency range of 100-300 ms at the Fz recording site. The wave

duration was the time from onset to offset.

The magnitude of the MMN at Fz was obtained by measuring the amplitude of the

difference waveform from the baseline to the peak amplitude of the MMN. In addition,

the RMS amplitude of the MMN was determined by taking the average RMS amplitude

within the time window of the MMN.

16

Results

Behavioral Results

For the behavioral experiment, the number of responses for /bɑ/ and /pɑ/ were

totaled in each group. The line graphs in Figure 2 describe how often each response was

chosen according to the stimulus presented. The graph in the upper left represents group

1, the English only group. Group 2, in the bottom left is the native Spanish group, and the

L2 Spanish group, group 3, is in the upper right. The graph in the bottom right shows all

three groups. The perceptual crossover from /bɑ/ to /pɑ/ occurred earliest with the native

Spanish group, as was expected. Perceptual crossover was at about 0 ms VOT. The

crossover for the English only listeners occurred about 10 ms later. The L2 Spanish group

crossed over in between the two.

A one-way ANOVA for VOT by group showed significant differences, F(2, 27) =

5.689, p < 0.009. A post hoc t-Test showed significant differences between group 1 and

group 2, t(18) = 2.877, p < 0.010 and between group 1 and group 3, t(18) = 2.946, p<

0.009; however, failed to reach significance between group 2 and group 3, t(18) = 0.004,

p < 0.997.

MMN Results

Descriptive statistics. The graphs in Figure 3 below show how often a MMN was

present and absent at each of the stimuli in each of the three groups. Figure 3A represents

the English only group, group1; Figure 3B represents the native Spanish group, group2;

and Figure 3C represents the L2 Spanish group, group 3.

The average peak latencies of the MMN for each of the stimuli in all 3 groups are

represented in Table 1. The average peak amplitudes are represented in Table 2. The

17

Figure 2. Mean identification functions for the /bɑ/-/pɑ/ continuum for each group are

represented in Figures 2A-2C. Figure 2D shows all three groups.

18

Figure 3. Graphs representing presence or absence of MMN in each group at each

stimulus.

19

Table 1

Descriptive Statistics for Average Peak Latencies (Plat) of the MMN

Group Stimulus VOT Plat Mean Plat SD Plat Min Plat Max

1 -40 ms 212.60 34.56 158.00 248.00

1 -30 ms 203.50 56.48 129.00 264.00

1 -20 ms 190.25 21.06 174.00 219.00

1 -10 ms 183.83 34.89 137.00 217.00

1 0 ms 196.11 51.74 132.00 272.00

1 10 ms 188.50 38.11 136.00 232.00

1 20 ms 208.57 53.16 155.00 279.00

1 30 ms 195.25 46.88 128.00 258.00

2 -40 ms 180.50 46.75 122.00 255.00

2 -30 ms 178.60 38.06 124.00 224.00

2 -20 ms 188.00 47.07 128.00 257.00

2 -10 ms 179.38 45.46 124.00 241.00

2 0 ms 204.80 57.52 125.00 269.00

2 10 ms 173.80 24.44 147.00 196.00

2 20 ms 169.00 27.96 142.00 207.00

2 30 ms 196.13 45.98 123.00 255.00

3 -40 ms 203.00 44.05 141.00 252.00

3 -30 ms 207.75 55.27 139.00 253.00

3 -20 ms 174.83 44.46 125.00 238.00

3 -10 ms 195.67 42.28 158.00 256.00

3 0 ms 177.63 29.71 137.00 217.00

3 10 ms 145.43 25.84 117.00 180.00

3 20 ms 159.50 38.02 104.00 200.00

3 30 ms 222.83 66.57 121.00 296.00

20

Table 2

Descriptive Statistics for Average Peak Amplitudes (Pamp) of the MMN

Group Stimulus VOT Pamp Mean Pamp SD Pamp Min Pamp Max

1 -40 ms -2.66 1.31 -4.50 -1.12

1 -30 ms -2.26 0.38 -2.65 -1.86

1 -20 ms -2.39 1.61 -5.00 -0.91

1 -10 ms -2.55 1.24 -4.50 -1.15

1 0 ms -2.45 1.09 -4.74 -0.75

1 10 ms -3.12 1.20 -5.78 -1.83

1 20 ms -2.30 0.85 -3.71 -1.32

1 30 ms -1.62 1.89 -2.98 2.80

2 -40 ms -2.39 0.75 -3.22 -1.34

2 -30 ms -2.86 0.50 -3.71 -2.37

2 -20 ms -1.93 0.48 -2.69 -1.47

2 -10 ms -2.41 0.72 -3.63 -1.49

2 0 ms -2.34 1.25 -3.91 -0.56

2 10 ms -1.61 0.86 -2.52 -0.49

2 20 ms -2.50 0.32 -2.71 -2.02

2 30 ms -2.32 0.73 -3.76 -1.52

3 -40 ms -2.66 1.47 -5.02 -0.99

3 -30 ms -1.62 0.39 -2.00 -1.19

3 -20 ms -3.05 2.27 -7.16 -1.14

3 -10 ms -2.19 1.26 -3.48 0.13

3 0 ms -2.83 2.03 -5.90 -0.42

3 10 ms -2.74 1.41 -5.43 -1.51

3 20 ms -2.17 1.49 -4.94 -0.41

3 30 ms -2.48 1.37 -4.13 -0.64

21

RMS amplitudes for each of the stimuli in each group at the CPZ electrode are found in

Table 3. The RMS amplitudes for all of the electrodes are found in Appendix D.

Scalp Distribution Within Groups

The grand averages for each group and stimulus were analyzed using scalp

distributions. Each figure represents the difference between the -50 VOT scalp

distribution and the VOT as stated on the individual figure. Each figure contains 25

individual maps representing an 8 ms time frame as labeled below each map.

Group 1 -40 ms VOT (Figure 4). The distribution shows some early negativity in

the left hemisphere at 90-97 ms. Some occipital negativity occurs first at 114 ms and then

again between 186 and 225 ms. The strongest occipital negativity occurs between 258

and 265 ms but is still relatively small. There are no large negativities in this distribution.

Group 1 -30 ms VOT (Figure 5). The first signs of negativity in this distribution

occur in the occipital region at 106 to 113 ms although they are very slight negativities.

Small occipital negativities also occur at 170 to 177 ms, and from 218 to 249 ms. These

negativities are again very small. The most prominent negativities occur between 258 and

289 ms in the frontal and temporal regions, showing strongest on the right side.

Group 1 -20 ms VOT (Figure 6). This distribution again shows some early

negative processing in the frontal and temporal regions from 90 to 105 ms. There is

scattered negativity throughout the distribution occurring maximally at 154 to 161 ms in

the left temporal region. As with earlier distributions, all negativities occur in only small

portions. There is also some positive processing shown first, at 138 to 145 ms, and again

from 242 to 265 ms, occurring maximally form 258 to 265 ms.

22

Table 3

Descriptive Statistics for RMS Amplitudes of the MMN at the CPZ Electrode

Group Stimulus VOT Mean SD Min Max

1 -40 ms -0.99 0.63 -1.55 -0.11

1 -30 ms -1.10 0.45 -1.68 -0.67

1 -20 ms -0.62 0.38 -0.93 0.01

1 -10 ms -1.02 1.00 -2.09 0.69

1 0 ms -0.90 0.49 -1.50 0.02

1 10 ms -1.49 1.09 -4.12 -0.78

1 20 ms -0.98 0.82 -2.55 0.17

1 30 ms -0.94 0.72 -1.64 0.46

2 -40 ms -1.10 0.79 -2.01 -0.03

2 -30 ms -1.00 0.34 -1.42 -0.59

2 -20 ms -0.94 0.44 -1.54 -0.33

2 -10 ms -1.18 0.51 -2.01 -0.36

2 0 ms -0.97 0.88 -1.87 0.42

2 10 ms -0.46 0.59 -0.99 0.53

2 20 ms -1.50 0.36 -1.98 -1.17

2 30 ms -1.28 0.63 -2.67 -0.74

3 -40 ms -0.87 0.53 -1.49 0.04

3 -30 ms 0.13 0.98 -1.17 0.99

3 -20 ms -1.61 1.54 -4.48 -0.38

3 -10 ms -0.73 1.01 -1.99 0.91

3 0 ms -1.33 1.52 -4.68 0.29

3 10 ms -1.47 0.92 -3.02 -0.52

3 20 ms -0.93 1.16 -2.73 0.51

3 30 ms -0.99 1.55 -2.93 1.59

23

Figure 4. Scalp distribution map for group 1 -40 ms VOT.

24


25


26

Group 1 -10 ms VOT (Figure 7). The first prominent negativities show up in this

distribution. First, frontally from 106 to 121 ms. Negativity recurs generally from 130 to

145 ms, strongest first in the right frontal and temporal regions then moving to the right.

Another prominent negativity occurs at 186 to 193 ms appearing mainly in the right

central and temporal areas. The strongest negativity occurs occipitally from 266 to

289 ms.

Group 1 0 ms VOT (Figure 8). Negativity shows up occipitally from 106 to 121

ms and again from 138 to 145 ms. A large negativity occurs generally from 218 to 241

ms with the largest negativity occurring from 226 to 233 ms. Although the negativity is

generalized to all areas during this time, it its strongest in the occipital area. Some smaller

occipital negativities persist during the last 40 ms of the distribution.

Group 1 10 ms VOT (Figure 9). This distribution is filled with large negativities.

The most prominent of these occur from 130 to 145 ms in the entire right hemisphere,

and again from 154 to 161ms and from 194 to 201 ms. There is, again, a very large

negativity from 226 to 233 ms, this time in the left hemisphere. Smaller negativities

persist from 258 to 289 ms.

Group 1 20 ms VOT (Figure 10). In this distribution prominent early negativity

occurs in the left temporal and occipital areas from 90 to 105 ms. Although some

negativity continues during the majority of the distribution, the largest and strongest

negativities occur frontally from 154 to 193 ms. The most prominent of these is from 154

to 161 ms.

Group 1 30 ms VOT (Figure 11). There is some early negative and positive

processing during this distribution, but there is nothing prominent until about 186 ms.

27


28

Figure 8. Scalp distribution map for group 1 0 ms VOT.

29


30


31


32

Large negativities occur from 210 to 233 ms and again from 250 to 257 ms, always

appearing strongest in the occipital areas.

Group 2 -40 ms VOT (Figure 12). The first distribution of group 2 contains many

small, scattered negativities throughout the distribution. The largest of these occur

frontally from 210 to 217 ms and from 242 to 257 ms. None of the negativities are very

large or prominent.

Group 2 -30 ms VOT (Figure 13). At -30 ms VOT negativities are again scattered

but occur slightly stronger and with less frequency than in the previous distribution.

There is some large left hemisphere negativity from 98 to 105 ms. From 106 to 193 ms

there is some frontal and occipital negativity. The most prominent of these occurs from

122 to 129 ms where the negativity is focused occipitally although it is also present in the

frontal and temporal areas.

Group 2 -20 ms VOT (Figure 14). The early portions of the -20 ms VOT

distribution show only small negativities. Prominent negativity appears at from 178 to

201 ms, showing strongest from 186 to 193 ms in the occipital and central areas. A

prominent left hemisphere negativity occurs from 226 to 241 ms with minor scattered

negativity after that.

Group 2 -10 ms VOT (Figure 15). Some strong negativity in the left frontal areas

occurs from 122 to 137 ms in the -10 ms VOT distribution. Large general negativity

occurs from 210 to 226 ms. Although the negativity is spread to all areas of the brain, the

strongest negativity is present in the left frontal quadrant. It is particularly strong from

218 to 225 ms.

33


34


35


36


37

Group 2 0 ms VOT (Figure 16). This distribution contains only light scattered

negativity throughout. The strongest of these occurs in the left hemisphere from 146 to

153 ms and in the frontal area from 282 to 289 ms.

Group 2 10 ms VOT (Figure 17). Small negativity is again scattered throughout

the distribution. A large negativity fills the central area from 138 to 145 ms with some

right hemisphere negativity lingering from 146 to 153 ms. Some large but relatively weak

negativity also occurs in the right hemisphere from 178 to 193 ms.

Group 2 20 ms VOT (Figure 18). Prominent negativity occurs throughout the left

and occipital areas from 122 to 129 ms during this distribution. From 130 to 137 ms

negativity is still strong in the left central and occipital areas, but has shifted from the left

frontal to right frontal area. The only other prominent negativity occurs frontally from

202 to 209 ms.

Group 2 30 ms VOT (Figure 19). The 30 ms VOT distribution is full of large

negativities beginning in the right central areas from 122 to 129 ms and from 138 to 146

ms. Large right central negativity occurs from 178 to 194 ms. There is another shift back

to the left from 218 ms to 234 ms. The most prominent negativity occurs from 242 to 257

ms where the negativity is spread throughout the brain. The negativity remains but

gradually diminishes for the remainder of the distribution.

Group 3 -40 ms VOT (Figure 20). There is some early processing in the frontal

areas from 98 to 122 ms. Prominent negativity is present in most of the front half of the

distribution from 210 to 249 ms. The strongest negativity is in the frontal portion.

Group 3 -30 ms VOT (Figure 21). This distribution again shows early frontal

negativity from 98 to 122 ms. Prominent negativity does not show up again until 250 ms

38


39


40


41


42


43


44

and lasts through 289 ms. The negativity is focused mostly in the right hemisphere with

some minor negativity on the left edge. Small negativity on the left edge is present

throughout most of the distribution.

Group 3 -20 ms VOT (Figure 22). Strong negativity is present centrally from 90

to 130 ms. From 138 to 145 ms the processing has shifted mainly to the right hemisphere.

The strongest negativity shows up from 90 to 105 ms and is focused near the frontal

areas. Strong frontal negativity is again present from 226 to 265 ms.

Group 3 -10 ms VOT (Figure 23). Strong general negativity shows up from 138 to

177 ms. The largest and most prominent negativity is present from 146 to 169 ms. During

this time the strongest negativity is focused toward the occipital region. Smaller

negativities are scattered throughout the distribution.

Group 3 0 ms VOT (Figure 24). As with most samples from this group, strong

negativity is present in the early processing from 90 to 113 ms. In this sample the focus is

near the occipital region. The negativity fades but shows up in the frontal portion from

130 to 153 ms. Other, smaller patches of negative processing are present near the

occipital region from 178 to 209 ms, frontally from 242 to 249 ms, and in a small patch in

the right hemisphere from 258 to 289 ms.

Group 3 10 ms VOT (Figure 25). Strong general negativity dominates the

distribution from 90 to 146 ms. Early on the negativity is strongest in the frontal and left

portions of the distribution and fades overall from 106 to 113 ms. The negativity comes

on strong again covering the entire map except the edges from 122 to 145 ms. Other

prominent negativities appear centrally and right temporally from 218 to 225 ms, and in

the right hemisphere from 274 to 289 ms.

45


46


47


48


49

Group 3 20 ms VOT (Figure 26). Strong negativity is limited from 122 ms to 129

ms where the entire map is dominated. Prior to that, from 106 to 121 ms negative

processing is found in the occipital and left temporal portions. Some occipital and right

temporal processing appears later on from 234 to 257 ms. See figure 26 below.

Group 3 30 ms VOT (Figure 27). Prominent negative processing is present from

106 to 121 ms focused mainly in the left hemisphere. Strong negativity shows up

frontally from 162 to 178 ms and again from 258 to 289 ms. Negativity dominates the

entire map from 274 to 281 ms and focuses in the frontal and left areas of the map.

Scalp Distribution Across Groups

The grand average scalp distributions were again analyzed using the brain maps.

This time the maps were analyzed across groups for each of the 8 stimuli.

-40 ms VOT. No prominent negativity shows up in either group 1 or group 2 with

the -40 ms VOT stimuli. Although group 2 shows slightly more negativity in the frontal

areas from 170 to 265 ms, the difference is minor. Group 3, however, shows prominent

frontal negativity from 210 to 249 ms.

-30 ms VOT. For the -30 ms VOT stimulus the most prominent processing is

again found in group 3, although the processing is very late, from 250 to 289 ms. Group 1

also shows some late processing but is not nearly as strong. Group 2 lacks the late

processing but shows some minor negativities in the intermediate times, particularly from

178 to 193 ms. Neither group 1 or group 3 show any prominent processing during this

time. Some early processing is found in groups 2 and 3, group 3 showing the stronger

negativities from 98 to 129 ms.

50


51


52

-20 ms VOT. At -20 ms VOT group 1 again shows the least amount of prominent

processing with only early perceptual processing showing up from 90 to 106 ms. Group 3

not only shows very strong early perceptual processing but also displays strong

processing from 122 to 145 ms. Very strong frontal negativity is also found from 226 to

257 ms. Group 2 lacks the early negativity but shows some strong negativity centrally

and occipitally from 186 to 201 ms. Some prominent negativity is also found overlapping

with that of group 3 from 226 to 241 ms although it is not as strong and is focused almost

completely in the left hemisphere.

-10 ms VOT. At -10 ms VOT group 1 finally shows some negative processing that

could represent a MMN. Frontal processing is present from 106 to 145 ms. Occipital

processing appears very late from 266 to 289 ms. Groups 2 and 3 still show more

prominent processing. Group 2 shows strong left hemisphere negativity from 122 to

137 ms and very strong negativity, again focused mainly on the left, from 210 to 233 ms.

Group 3 shows very strong negativity earlier than does group 2. The strongest negativity

is from 138 to 177 ms.

0 ms VOT. The differences found at 0 ms VOT are unexpected as group 2 shows

almost no negativity. Only very small negativities from 138 to 146 ms seem to have any

significance. Group 1 shows very strong negativity focused mainly in the occipital

portion from 218 to 226 ms. Group 3 again shows the most processing with strong early

perceptual processing from 90 to 113 ms and more strong frontal negativity from 130 to

153 ms. Smaller occipital and right central processing is found throughout the rest of the

distribution, particularly from 194 to 217 ms.

53

10 ms VOT. Strong negativities are present in all three groups at 10 ms VOT. The

strong negativities are limited in group 2 showing up only from 138 to 145 ms. Limited

smaller negativities are also found from 146 to 153 ms and from 178 to 193 ms. Groups 1

and 3 display extensive prominent negative processing. While the negativity in group 3 is

clustered together lasting from 90 to 161 ms and fading after that, group 1 has strong

negative processing spread throughout the distribution. The strongest negativities are

from 130 to 145 ms, from 154 to 161 ms, from 194 to 201 ms, from 226 to 233 ms, and

from 266 to 289 ms.

20 ms VOT. At 20 ms VOT all 3 groups again show some prominent processing,

but less than at 10 ms. Group 1 displays strong frontal processing from 146 to 193 ms.

Group 2 again shows less, but strong negativity is present from 122 to 137 ms. Group 3

displays very strong processing only from 122 to 129 ms, with some prominent

processing on before and after. There is also some strong occipital negativity from 234 to

257 ms.

30 ms VOT. All three groups show scattered but strong negative processing at 30

ms VOT. Group 1 lacks negativity in the early stages but shows strong processing from

186 to 201 ms, from 210 to 233 ms, and from 250 to 257 ms. Group 2 displays small

spots of strong negativity from 122 to 129 ms and from 138 to 153 ms. More wide spread

negativity is found from 170 to 201 ms and from 210 to 273 ms. The focus of the

negativity shifts significantly as time passes. Group 3 shows strong negative processing

that is not quite as sporadic as in group 2, but more spread out than in group 1. Early

processing is found from 106 to 121 ms. Very strong processing then occurs from 162 to

185 ms. The very late stages from 258 to 289 ms also show some strong processing.

54

Statistical Analysis

A multivariate analysis of variance for the independent variables of groups and

stimuli failed to show any significant F ratios at p ≤ .05.

55

Discussion

The present study examined /bɑ/-/pɑ/ speech sound discrimination in 3 different

groups of listeners using an array of stimuli on a VOT continuum from -50 ms to 30 ms.

The -50 ms stimulus was used as the standard and all other stimuli were compared to it as

the deviants in an odd-ball paradigm to elicit the MMN. At some point in that continuum

the difference between the standard and the deviant stimuli represented a WC change for

native English listeners and an AC change for native Spanish listeners. The group of

interest was those who had learned Spanish as a second language. It was of interest to

know if they were able to make the sound discrimination that native Spanish listeners

make when the sound pair represents a WC change for native English listeners and

whether or not the MMN shows this discrimination.

Statistical analysis of the behavioral data showed a significant difference between

native Spanish listeners and English-only listeners regarding when they perceive /pɑ/

instead of /bɑ/. There was also a significant difference between L2 Spanish listeners and

English-only listeners, but not between native Spanish listeners and L2 Spanish listeners.

This indicates that the L2 Spanish listeners’ ability to distinguish Spanish speech sounds

was similar to that of the native Spanish listeners, and it was better than the English only

listeners.

Although statistical analysis of the groups and stimuli at the CPZ electrode was

not significant, the difference in strong negativities shown on the distribution maps

support the theory explored in previous studies that underlying neural-sensory

representations of speech may be altered by linguistic experiences (Dehaene-Lambertz,

1997). Analysis using groupings of electrodes or looking at all electrodes may have

56

shown significant differences and future studies should address different methods of

analysis. The differences between the three groups found in the distribution maps did not

occur at the same place as those found in the behavioral data. Scalp distribution maps

showed strong negativity within the time frame of the MMN at -20 and -10 ms VOT in

both the native Spanish and L2 Spanish listeners, while English only listeners did not

show strong negativity within the time frame of the MMN until 0 ms VOT. The anomaly

is that at 0 ms VOT, where behavioral data showed that native Spanish listeners had

begun to perceive /pɑ/ about 40% of the time and English-only listeners were at about

10%, very little negativity appeared in the native Spanish listeners’ maps. At 10 ms VOT

all three groups showed strong negativities in the time frame of the MMN but the native

Spanish listeners showed the weakest negativities. The reason for these weak negativities

at 0 ms in native Spanish listeners is unclear. One possibility is that the behavioral task is

more sensitive than the MMN to VOT.

Both the behavioral and the electrophysiological data showed differences between

the groups, but the differences did not correspond. The behavioral data showed a

separation between 0 and 20 ms VOT, where native Spanish listeners perceived a

difference between /bɑ/ and /pɑ/ slightly earlier than did English only listeners, and L2

Spanish listeners were in between. The electrophysiological data showed a distinction

between -20 and 0 ms VOT where native Spanish and L2 Spanish listeners perceived a

difference between /bɑ/ and /pɑ/ 20 ms earlier than did English only listeners. Previous

studies using the MMN to test L2 learning have not reported any differences between

behavioral and electrophysiological results (Nenonen et al., 2005; Shestakova et al.,

2003; Winkler & Kujala et al., 1999). Studies such as that by Sharma and Dorman (2000)

57

that explored the MMN in cross-language phonetic perception without exploring an L2

similarly did not show a discrepancy between behavioral and electrophysiological data.

The major difference between the current study and these studies is that none of them

used a large continuum of stimulus tokens. They used only one or two stimulus pairs and

any significant difference between behavioral and MMN data might have contradicted

the findings of their study. Although a difference existed in the current study between

behavioral and MMN data, both sets of data support the theory that L2 language learning

may alter underlying neural-sensory representations of speech. More research must be

done in order to determine if this discrepancy is an anomaly to this study or if similar

patterns could be found in other languages or with other phoneme comparisons.

Overall, the findings from the study support the work by Winkler & Kujala et al.

(1999). Their study using Hungarian-only listeners, Hungarians fluent in Finnish, and

native Finnish listeners, similarly found that when tested on Finnish vowel contrasts not

found in Hungarian, an MMN response was not elicited in the Hungarian-only listeners.

The MMN was elicited in the other two groups, however. The researchers concluded that

L2 listeners developed cortical memory representations for the phoneme system of the

new language enabling them to process these phonemes pre-attentively as do native

listeners. The current study similarly concludes that the loss of non-native speech sound

discrimination abilities that seems to occur after 6-8 months of age and the regaining of

these abilities in adulthood after an L2 is learned is apparently not due merely to

attentional bias. Research by Shestakova et al. (2003) was conducted using Finnish

children learning French as an L2, who had only been exposed to the new language for

12-16 weeks. Despite the limited exposure, they too found that L2 learners had increased

58

MMN magnitudes over Finnish-only children when presented with French vowel

contrasts.

Future studies should continue to explore the effect of L2 learning on neural-

sensory representations of speech. Non-native consonant contrasts other than the /bɑ/-

/pɑ/ contrast, and other language comparisons besides English-Spanish should be done.

Such studies could help to explain whether there are differences between L2 learning of

vowels and L2 learning of consonants. Up until now most L2 studies using the MMN

have focused on vowels and have shown that the neural-sensory representations of speech

are affected in L2 learners (Shestakova et al., 2003; Winkler & Kujala et al., 1999). The

current study tested consonants that differed in VOT and demonstrated the same thing,

but there are aspects of consonant distinction, other than VOT, such as place of

articulation that could be explored to shed more light on how the brain learns a new

language.

59

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APPENDIXES

Appendix A

Informed Consent Document

CONSENT TO ACT AS A HUMAN RESEARCH SUBJECT Speech Sound Discrimination in L2 Spanish Listeners David L. McPherson, Ph.D. Department of Audiology and Speech Language Pathology Brigham Young University (801) 422-6458 Name of Participant: _____________________________ Date of Birth: _____________ Purpose of Study: This investigation is designed to study how the brain processes nonnative speech sounds in second language learners. Participation in this study will help scientists better understand how second languages are learned in adulthood. Procedures: I have been asked to participate in a research study being conducted by Dr. David L. McPherson and/or such assistants as may be selected by him. The study will be conducted in room 109 and 111 of the John Taylor Building on the Brigham Young University campus. I will be asked questions but do not have to answer any questions that I do not want to answer. Participation in this study, including orientation and testing, requires two sessions, equaling about 2 hours, total. These two sessions will be scheduled on separate days, but it is possible for the two sessions to be combined into one visit. The first session will be for a hearing screening and a question and answer session, which should last approximately 20 minutes. The second session will be for the actual data collection, which should last about 1 ½ hours. I have been advised that these times are an estimate, and it may take more or less time, depending on how easy it is to set up the equipment. I may ask for a break at any time during testing. I will be given a standard hearing test screening. My ears will be looked into with a scope, my eardrums will be tested to see how they move, and my hearing will be tested. Surface electrodes (metal discs about the size of a dime) will be used to record electrical activity of the brain. These discs will be applied to the surface of the skin with a gel and are easily removed with water. Blunt needles will be used as a part of this study to help apply the electrode gel, but they will never be used to puncture the skin. Electrical activity of my brain will be recorded, but no electrical impulses/shocks will be applied to the brain. This is similar to what is known as an “EEG” or brain wave test. These procedures show actual measurements of normal, continuous, electrical activity in the brain. Some sounds will be presented though earphones. I will be asked to push one button when the sounds are the same and another when they are different. These clinical procedures are routine, similar to those used to test hearing, although some techniques of

65

analysis are experimental. Risks: There may be some local skin irritation resulting from the electrode discs. This will be treated in the usual manner by removing the discs and exposing the area to air, which results in alleviation of the irritation. Another possible, but unlikely, discomfort would be if the scalp received an abrasion when the blunt needle is used to place the electrode gel. The electrodes would be removed immediately, and any gel on the injured site would be removed. If this were to occur I would be given the option to discontinue my participation in the study. There are no other known risks with this procedure. Benefits: Possible benefits from participating in this study will be the assessment of my hearing. I will be notified of any irregularities in my ears (structures) and/or hearing abilities found during the routine hearing tests. If irregularities are discovered, I may be advised to have a professional examine my ears/hearing, or I may be advised of possible treatments (if any). These procedures will benefit me by providing (possible) early treatment. I also understand there may be no direct benefit to me. However, the information obtained will help people further understand how the brain processes auditory information and about differences in these processes between native speakers of a language and second language learners. Confidentiality: Participation in this study is voluntary and I have a right to refuse to participate or withdraw at any time, without penalty. All information obtained from testing is strictly confidential and is protected under the laws governing privacy. No information specifically pertaining to me, other than reporting of test results without identifying information may be released without my signature. All identifying references will be removed and replaced by control numbers which will identify any disclosed or published data. Data collected in this study will be stored in a secured area accessible only to personnel associated with the study. Other Considerations: There are no charges incurred by me for participation in this study. There is no treatment or intervention involved in this study although I may be counseled to seek such treatment or intervention. I understand that for any reason I may withdraw from the study at any time without penalty. The procedures listed above have been explained to me by: __________________ in a satisfactory manner and my questions relating to such risks and procedures have been answered. If I have any questions about the research I may ask any of the investigators or contact Dr. David L. McPherson, Audiology and Speech-Language Pathology, 129 TLRB, Provo, Utah 84602-8633; email: [email protected]; phone: 801-422-6458. If I have any questions as to my rights as a participant in this research project I may contact Renea Beckstrand, Chair of Institutional Review Board, email: [email protected]; phone: 801-422-3873. I consent to participate in the above explained study. __________________________________ ________________ Signature of Participant Date

66

Appendix B Words Used for Stimulus Recordings

/pɑ/ words

Paca (bale, pack)

Pase (pass, come in)

Pala (shovel)

Paño (cloth)

Panda (Panda, group)

Pasta (paste)

/bɑ/ words

Baca (roof, rack)

Base (base)

Bala (bullet)

Baño (bathroom)

Banda (band, ribbon)

Basta (enough)

67

Appendix C

List of Sentences Read by Speaker

Diga la palabra paca otra vez.

Diga la palabra pala otra vez.

Diga la palabra basta otra vez.

Diga la palabra banda otra vez.


Diga la palabra baño otra vez.

Diga la palabra bala otra vez.

Diga la palabra base otra vez.

Diga la palabra paño otra vez.

Diga la palabra panda otra vez.

Diga la palabra baca otra vez.

Diga la palabra pasta otra vez.































68



















69

Appendix D

Tables of RMS Amplitudes

Table D1

Descriptive Statistics for RMS Amplitudes of the Mismatch Negativity for Group 1 with Stimulus of -40 ms VOT

Location Mean SD Min Max

O2 0.02 0.35 -0.31 0.60

O1 0.47 0.96 -0.36 2.13

OZ 0.04 0.35 -0.47 0.44

PZ -0.73 0.52 -1.36 0.04

P4 -0.57 0.69 -1.42 0.37

CP4 -0.73 0.88 -1.96 0.31

P8 -0.42 0.55 -1.06 0.22

C4 -1.03 1.02 -2.52 0.23

TP8 -0.43 0.56 -1.05 0.30

T8 -0.60 0.61 -1.62 -0.17

P7 0.15 0.35 -0.25 0.45

P3 -0.21 0.53 -0.99 0.49

CP3 -0.41 0.55 -0.98 0.51

CPZ -0.99 0.63 -1.55 -0.11

CZ -1.09 0.80 -1.74 0.26

FC4 -1.13 1.19 -3.05 0.21

FT8 -0.78 0.94 -2.44 -0.18

TP7 -0.06 0.47 -0.61 0.44

C3 -0.60 0.63 -1.05 0.45

FCZ -1.33 0.89 -2.27 0.14

FZ -1.41 1.19 -3.25 0.05

F4 -1.06 1.27 -3.24 0.09

F8 -0.86 1.07 -2.74 -0.18

T7 -0.37 0.56 -0.90 0.54

FT7 -0.44 0.74 -1.28 0.56

FC3 -1.13 0.70 -1.73 0.00

F3 -1.06 0.88 -2.26 0.12

70

FP2 -0.58 1.34 -2.88 0.48

F7 -0.66 0.79 -1.63 0.53

FP1 -0.67 1.07 -2.38 0.57

71

Table D2



O2 -0.10 0.65 -0.83 0.70

O1 -0.13 0.31 -0.34 0.32

OZ -0.31 0.53 -0.96 0.34

PZ -0.98 0.89 -1.85 0.25

P4 -0.93 0.48 -1.47 -0.33

CP4 -1.24 0.41 -1.85 -0.97

P8 -0.46 0.29 -0.85 -0.16

C4 -1.19 0.38 -1.62 -0.82

TP8 -0.67 0.21 -0.87 -0.39

T8 -0.84 0.19 -1.11 -0.67

P7 0.06 0.78 -0.54 1.21

P3 -0.25 1.04 -1.22 1.18

CP3 -0.63 1.11 -1.77 0.74

CPZ -1.10 0.45 -1.68 -0.67

CZ -1.07 0.37 -1.60 -0.79

FC4 -1.05 0.44 -1.64 -0.60

FT8 -0.73 0.38 -1.15 -0.23

TP7 -0.03 0.91 -0.94 1.22

C3 -0.63 1.18 -1.96 0.80

FCZ -0.80 0.24 -1.00 -0.46

FZ -0.55 0.23 -0.81 -0.31

F4 -0.99 0.63 -1.56 -0.13

F8 -0.82 0.48 -1.40 -0.23

T7 -0.04 0.94 -0.86 1.26

FT7 0.08 0.89 -0.84 1.29

FC3 -0.28 0.63 -0.86 0.50

F3 -0.03 0.34 -0.42 0.39

FP2 -0.73 0.79 -1.48 0.17

F7 0.06 0.89 -0.83 1.29

FP1 -0.31 0.09 -0.41 -0.23

72

Table D3



O2 -0.56 0.66 -1.48 0.21

O1 -0.22 0.55 -0.93 0.34

OZ 0.05 0.56 -0.59 0.70

PZ -0.57 1.08 -1.43 1.31

P4 -1.24 1.32 -3.48 -0.05

CP4 -0.93 0.52 -1.71 -0.29

P8 -0.46 0.68 -0.99 0.53

C4 -0.54 0.32 -0.92 -0.22

TP8 -0.35 0.58 -0.93 0.45

T8 -0.29 0.51 -0.92 0.16

P7 0.16 0.83 -0.68 1.44

P3 -0.27 0.68 -1.04 0.41

CP3 -0.21 0.53 -0.85 0.43

CPZ -0.62 0.38 -0.93 0.01

CZ -0.55 0.43 -1.11 -0.02

FC4 -0.23 0.54 -0.87 0.58

FT8 0.08 0.57 -0.80 0.79

TP7 0.25 0.75 -0.57 1.46

C3 -0.22 0.47 -0.83 0.49

FCZ -0.67 0.74 -1.31 0.45

FZ -0.30 0.81 -1.32 0.66

F4 -0.07 0.80 -1.12 1.02

F8 -0.01 0.74 -1.20 0.79

T7 0.02 0.43 -0.73 0.31

FT7 0.04 0.45 -0.75 0.38

FC3 -0.19 0.54 -0.78 0.69

F3 -0.05 0.63 -0.81 0.66

FP2 -0.14 0.79 -1.32 0.58

F7 -0.02 0.42 -0.75 0.31

FP1 -0.01 0.66 -0.88 0.58

73

Table D4



O2 -0.11 0.54 -0.96 0.37

O1 0.17 0.70 -1.12 0.99

OZ 0.06 0.72 -1.19 1.00

PZ -0.88 0.81 -1.99 0.37

P4 -0.58 0.78 -1.30 0.93

CP4 -0.70 0.96 -1.36 1.18

P8 -0.35 0.30 -0.66 0.11

C4 -0.53 1.17 -1.51 1.65

TP8 -0.40 0.21 -0.61 -0.12

T8 -0.33 0.58 -1.25 0.43

P7 0.02 1.02 -1.47 1.69

P3 -0.38 1.02 -1.99 0.98

CP3 -0.51 1.15 -1.89 1.44

CPZ -1.02 1.00 -2.09 0.69

CZ -0.87 0.99 -1.88 0.85

FC4 -0.14 1.21 -1.39 1.96

FT8 -0.24 0.83 -1.60 0.73

TP7 0.11 0.87 -0.99 1.66

C3 -0.55 0.81 -1.58 0.72

FCZ -0.61 1.04 -1.64 1.14

FZ -0.30 0.73 -1.31 0.64

F4 -0.13 0.81 -1.22 0.81

F8 -0.14 0.82 -1.60 0.67

T7 0.03 0.61 -0.79 1.09

FT7 0.06 0.50 -0.26 1.07

FC3 -0.45 0.47 -0.90 0.36

F3 -0.42 0.28 -0.88 -0.12

FP2 -0.09 1.02 -1.64 1.39

F7 0.02 0.52 -0.33 1.06

FP1 -0.58 0.51 -1.45 0.13

74

Table D5

Descriptive Statistics for RMS Amplitudes of the Mismatch Negativity for Group 1 with Stimulus of 0 ms VOT


O2 -0.84 0.61 -1.76 0.06

O1 -0.61 0.48 -1.48 0.29

OZ -0.78 0.57 -1.48 0.31

PZ -1.02 0.51 -1.62 -0.11

P4 -1.02 0.99 -2.62 0.61

CP4 -0.86 0.83 -1.61 0.91

P8 -0.53 0.85 -2.42 0.91

C4 -0.54 0.87 -1.62 1.39

TP8 -0.42 0.94 -2.23 1.41

T8 -0.37 0.87 -1.59 1.56

P7 -0.02 0.53 -0.93 1.00

P3 -0.58 0.50 -1.48 0.25

CP3 -0.47 0.56 -1.15 0.90

CPZ -0.90 0.49 -1.50 0.02

CZ -0.71 0.91 -1.89 1.15

FC4 -0.44 1.21 -1.90 1.72

FT8 -0.48 1.03 -2.74 1.17

TP7 0.09 0.51 -0.87 1.01

C3 -0.43 0.70 -1.35 1.38

FCZ -0.55 1.17 -1.97 1.51

FZ -0.38 1.17 -1.53 1.73

F4 -0.36 1.11 -1.77 1.51

F8 -0.43 1.16 -2.89 1.34

T7 0.16 0.48 -0.52 1.19

FT7 0.03 0.62 -0.73 1.22

FC3 -0.46 0.89 -1.63 1.73

F3 -0.23 0.88 -1.00 1.89

FP2 -0.37 1.05 -2.22 1.10

F7 0.07 0.77 -1.21 1.21

FP1 -0.14 0.97 -1.85 1.74

75

Table D6



O2 -0.58 0.75 -1.96 0.40

O1 -0.62 0.40 -1.30 -0.08

OZ -0.36 0.58 -1.59 0.34

PZ -1.28 0.71 -2.79 -0.69

P4 -1.06 0.62 -2.14 -0.22

CP4 -0.96 0.75 -2.46 -0.17

P8 -0.49 0.54 -1.56 -0.03

C4 -0.79 0.73 -2.06 -0.03

TP8 -0.19 0.30 -0.51 0.36

T8 0.05 0.50 -0.62 0.72

P7 -0.29 0.42 -1.31 -0.02

P3 -0.97 0.77 -1.96 0.01

CP3 -1.17 0.79 -2.58 -0.26

CPZ -1.49 1.09 -4.12 -0.78

CZ -1.46 1.24 -4.28 -0.37

FC4 -0.74 0.99 -2.56 0.59

FT8 0.15 0.60 -0.58 0.98

TP7 -0.31 0.30 -1.01 -0.03

C3 -1.13 0.83 -2.59 0.03

FCZ -1.33 1.31 -4.29 -0.27

FZ -0.91 1.29 -3.46 0.60

F4 -0.46 0.99 -2.01 1.02

F8 0.15 0.67 -0.72 1.09

T7 -0.29 0.32 -0.99 -0.01

FT7 -0.36 0.34 -0.98 0.01

FC3 -0.87 1.08 -2.90 0.76

F3 -0.77 0.87 -2.38 0.17

FP2 -0.17 0.78 -1.30 0.87

F7 -0.39 0.35 -1.01 0.01

FP1 -0.57 0.61 -1.56 0.32

76

Table D7



O2 -0.25 0.73 -1.36 1.01

O1 -0.03 0.98 -0.95 1.84

OZ -0.08 0.80 -1.00 1.35

PZ -0.88 0.60 -1.70 -0.03

P4 -0.47 0.79 -1.80 0.52

CP4 -0.56 1.21 -2.75 0.93

P8 -0.25 0.62 -1.10 0.48

C4 -0.79 1.25 -3.20 0.90

TP8 -0.18 0.78 -1.32 0.78

T8 -0.51 0.81 -1.89 0.38

P7 0.18 0.72 -0.98 1.29

P3 -0.33 0.62 -1.26 0.67

CP3 -0.57 0.66 -1.69 0.04

CPZ -0.98 0.82 -2.55 0.17

CZ -1.18 0.98 -3.32 -0.43

FC4 -1.06 1.16 -3.60 -0.23

FT8 -0.54 0.68 -1.55 0.46

TP7 0.08 0.77 -1.00 1.26

C3 -0.77 0.86 -2.52 -0.13

FCZ -1.36 1.10 -3.76 -0.68

FZ -1.31 1.23 -3.96 -0.48

F4 -1.21 1.07 -3.17 -0.18

F8 -0.52 0.97 -2.45 0.45

T7 -0.22 0.64 -1.17 0.55

FT7 -0.29 0.73 -1.56 0.57

FC3 -0.95 1.32 -3.75 0.18

F3 -0.95 1.18 -3.50 -0.15

FP2 -0.76 0.92 -2.03 0.16

F7 -0.41 0.76 -1.55 0.57

FP1 -0.55 0.66 -1.56 0.35

77

Table D8



O2 -0.09 0.53 -0.94 0.53

O1 -0.31 0.71 -1.17 0.92

OZ -0.21 0.54 -0.81 0.65

PZ -0.77 0.73 -1.63 0.66

P4 -0.61 0.80 -1.56 1.01

CP4 -0.63 0.82 -1.21 1.07

P8 -0.08 0.50 -0.84 0.54

C4 -0.61 0.88 -1.57 1.13

TP8 -0.03 0.53 -0.76 0.66

T8 0.11 0.45 -0.38 0.78

P7 -0.43 0.48 -1.21 0.24

P3 -0.77 0.78 -1.77 0.85

CP3 -0.92 0.79 -2.05 0.60

CPZ -0.94 0.72 -1.64 0.46

CZ -0.91 0.71 -1.86 0.22

FC4 -0.70 0.89 -1.61 0.80

FT8 0.00 0.57 -0.72 1.24

TP7 -0.51 0.37 -0.99 0.15

C3 -0.87 0.68 -1.82 0.31

FCZ -0.96 0.94 -2.19 0.33

FZ -1.01 0.93 -2.17 0.15

F4 -0.82 1.00 -2.27 0.54

F8 0.00 0.64 -0.87 1.27

T7 -0.47 0.48 -1.26 0.10

FT7 -0.56 0.68 -1.85 0.10

FC3 -1.07 0.82 -2.41 -0.10

F3 -0.92 0.98 -2.40 0.67

FP2 -0.44 0.68 -1.61 0.82

F7 -0.47 0.74 -1.81 0.58

FP1 -0.52 0.63 -1.51 0.64

78

Table D9



O2 -0.26 0.91 -1.47 0.74

O1 -0.61 0.65 -1.57 0.28

OZ -0.49 0.53 -1.29 0.07

PZ -0.74 0.94 -2.20 0.28

P4 -0.67 0.93 -1.86 0.16

CP4 -0.71 0.98 -2.01 0.27

P8 -0.41 0.90 -1.74 0.44

C4 -0.95 1.00 -2.52 -0.02

TP8 -0.42 0.65 -1.28 0.25

T8 -0.34 0.78 -1.49 0.71

P7 -0.50 0.44 -1.04 0.23

P3 -0.84 0.62 -1.61 -0.11

CP3 -1.18 0.53 -1.63 -0.37

CPZ -1.10 0.79 -2.01 -0.03

CZ -1.28 0.67 -2.13 -0.33

FC4 -0.82 0.82 -2.31 0.04

FT8 -0.22 0.85 -1.50 0.93

TP7 -0.49 0.48 -1.02 0.25

C3 -1.08 0.52 -1.60 -0.45

FCZ -1.22 0.76 -2.13 -0.03

FZ -1.16 0.65 -1.95 -0.01

F4 -0.67 0.92 -1.87 0.28

F8 -0.35 0.75 -1.52 0.58

T7 -0.55 0.53 -1.25 0.26

FT7 -0.39 0.42 -0.94 0.10

FC3 -1.12 0.53 -1.73 -0.34

F3 -0.83 0.60 -1.46 0.01

FP2 -0.37 0.99 -1.51 1.00

F7 -0.37 0.52 -1.11 0.24

FP1 -0.55 0.89 -1.71 0.57

79

Table D10



O2 -0.58 0.74 -1.62 0.40

O1 -0.06 0.56 -0.76 0.78

OZ -0.33 0.90 -1.57 0.81

PZ -0.66 0.65 -1.27 0.11

P4 -0.66 0.90 -1.50 0.48

CP4 -0.69 0.68 -1.19 0.43

P8 -0.43 0.48 -0.88 0.25

C4 -0.63 0.49 -1.00 0.08

TP8 -0.32 0.44 -0.88 0.14

T8 -0.29 0.58 -0.93 0.46

P7 -0.26 0.36 -0.61 0.20

P3 -0.94 0.45 -1.52 -0.45

CP3 -1.02 0.66 -2.12 -0.51

CPZ -1.00 0.34 -1.42 -0.59

CZ -0.73 0.38 -1.27 -0.30

FC4 -0.81 0.16 -1.02 -0.58

FT8 -0.29 0.68 -1.21 0.28

TP7 -0.27 0.51 -0.86 0.31

C3 -0.72 0.51 -1.46 -0.04

FCZ -0.52 0.48 -0.97 0.26

FZ -0.39 0.47 -0.74 0.37

F4 -0.41 0.53 -1.06 0.37

F8 -0.15 0.70 -1.17 0.62

T7 -0.17 0.64 -0.87 0.49

FT7 -0.15 0.85 -1.15 0.74

FC3 -0.47 0.65 -1.25 0.41

F3 -0.39 0.86 -1.50 0.60

FP2 -0.14 0.67 -1.15 0.47

F7 -0.01 0.82 -0.99 0.83

FP1 -0.24 0.79 -1.52 0.52

80

Table D11



O2 -0.65 0.52 -1.44 0.04

O1 -0.38 0.80 -1.22 0.57

OZ -0.59 0.71 -1.61 0.11

PZ -0.63 0.11 -0.74 -0.45

P4 -0.61 0.34 -1.13 -0.28

CP4 -0.79 0.59 -1.48 0.12

P8 -0.54 0.50 -1.11 0.22

C4 -0.67 0.83 -1.34 0.67

TP8 -0.69 0.60 -1.42 0.18

T8 -0.44 0.94 -1.23 0.77

P7 -0.32 0.67 -1.18 0.22

P3 -0.83 0.79 -2.12 0.00

CP3 -0.73 0.63 -1.83 -0.27

CPZ -0.94 0.44 -1.54 -0.33

CZ -0.56 0.77 -1.07 0.70

FC4 -0.58 1.03 -1.53 0.90

FT8 -0.41 1.01 -1.34 0.78

TP7 -0.23 0.76 -1.12 0.48

C3 -0.70 0.54 -1.63 -0.23

FCZ -0.07 1.25 -1.53 1.60

FZ -0.41 0.89 -1.16 0.98

F4 -0.48 1.10 -1.75 0.94

F8 -0.22 1.01 -1.37 0.82

T7 -0.32 0.64 -1.26 0.28

FT7 -0.20 0.80 -1.31 0.83

FC3 -0.51 0.66 -1.40 0.44

F3 -0.40 0.69 -1.22 0.65

FP2 -0.16 1.07 -1.40 1.06

F7 -0.03 0.56 -0.54 0.83

FP1 -0.01 0.65 -0.44 1.13

81

Table D12



O2 -0.42 0.60 -1.18 0.66

O1 -0.32 0.67 -0.95 1.03

OZ -0.26 0.72 -0.97 1.15

PZ -0.88 0.43 -1.48 -0.10

P4 -0.70 0.32 -1.25 -0.32

CP4 -1.14 0.76 -2.82 -0.27

P8 -0.65 0.42 -1.16 0.15

C4 -1.07 0.53 -2.14 -0.57

TP8 -0.64 0.80 -2.11 0.59

T8 -0.56 1.01 -2.14 0.98

P7 -0.52 0.55 -1.27 0.19

P3 -0.77 0.63 -1.56 0.21

CP3 -1.04 0.68 -2.10 0.04

CPZ -1.18 0.51 -2.01 -0.36

CZ -1.26 0.76 -2.66 -0.33

FC4 -1.09 0.55 -1.93 -0.39

FT8 -0.76 1.18 -2.88 0.58

TP7 -0.53 0.56 -1.42 0.24

C3 -1.18 0.84 -2.82 0.01

FCZ -1.37 0.55 -2.25 -0.59

FZ -1.24 0.71 -2.24 -0.31

F4 -1.08 0.76 -2.66 -0.20

F8 -0.65 1.14 -3.14 0.42

T7 -0.61 0.55 -1.36 0.48

FT7 -0.69 0.44 -1.33 0.07

FC3 -1.13 0.66 -1.75 0.09

F3 -0.95 0.65 -2.25 -0.25

FP2 -0.89 1.26 -3.69 0.46

F7 -0.73 0.54 -1.37 0.06

FP1 -0.84 0.99 -3.05 0.23

82

Table D13



O2 -0.11 0.50 -1.01 0.19

O1 -0.08 1.08 -0.83 1.81

OZ -0.09 0.84 -0.67 1.37

PZ -0.55 1.00 -1.40 0.97

P4 -0.41 0.47 -0.82 0.31

CP4 -0.77 0.60 -1.35 -0.02

P8 -0.15 0.71 -0.81 1.03

C4 -0.87 0.87 -1.65 0.53

TP8 -0.26 0.46 -0.75 0.42

T8 -0.35 0.56 -1.00 0.44

P7 -0.20 0.76 -0.74 1.11

P3 -0.55 0.88 -1.35 0.86

CP3 -0.75 0.81 -1.36 0.64

CPZ -0.97 0.88 -1.87 0.42

CZ -1.21 0.85 -1.89 0.26

FC4 -1.14 0.75 -1.90 0.08

FT8 -0.70 0.24 -0.93 -0.35

TP7 -0.42 0.81 -0.98 0.98

C3 -1.01 0.62 -1.45 0.01

FCZ -1.24 0.88 -1.97 0.23

FZ -0.91 0.75 -1.53 0.33

F4 -1.02 0.52 -1.47 -0.17

F8 -0.77 0.25 -1.15 -0.51

T7 -0.39 0.49 -1.00 0.30

FT7 -0.17 0.63 -0.72 0.71

FC3 -0.93 0.94 -1.63 0.60

F3 -0.74 0.70 -1.33 0.46

FP2 -0.65 0.50 -1.24 0.09

F7 0.05 0.91 -0.71 1.52

FP1 -0.13 1.00 -0.90 1.45

83

Table D14



O2 -0.35 0.42 -1.03 0.05

O1 -0.56 0.39 -1.01 -0.16

OZ -0.77 0.75 -2.00 -0.20

PZ -0.54 0.39 -0.92 -0.03

P4 -0.59 0.76 -1.45 0.31

CP4 -0.57 0.86 -1.38 0.36

P8 -0.32 0.70 -0.99 0.45

C4 -0.43 0.97 -1.49 0.74

TP8 -0.24 0.78 -0.91 0.67

T8 -0.25 0.87 -1.15 0.79

P7 0.01 0.53 -0.40 0.90

P3 -0.26 0.29 -0.60 -0.01

CP3 -0.10 0.44 -0.60 0.36

CPZ -0.46 0.59 -0.99 0.53

CZ -0.35 0.73 -0.82 0.86

FC4 -0.56 1.04 -1.56 0.94

FT8 -0.24 0.87 -0.87 1.10

TP7 0.14 0.43 -0.32 0.75

C3 -0.04 0.58 -0.56 0.88

FCZ -0.23 0.85 -0.84 1.17

FZ -0.22 0.84 -1.30 1.03

F4 -0.42 1.07 -1.54 1.22

F8 -0.29 0.93 -1.22 1.10

T7 0.21 0.60 -0.39 1.19

FT7 0.20 0.48 -0.37 0.77

FC3 -0.19 0.61 -0.49 0.91

F3 -0.16 0.56 -0.79 0.74

FP2 -0.20 1.03 -1.49 1.36

F7 0.26 0.26 -0.01 0.60

FP1 0.07 0.72 -0.96 1.01

84

Table D15



O2 -0.52 0.24 -0.84 -0.27

O1 -0.73 0.43 -1.16 -0.35

OZ -0.92 0.47 -1.44 -0.38

PZ -1.41 0.35 -1.75 -1.05

P4 -0.65 0.80 -1.11 0.54

CP4 -0.83 0.75 -1.43 0.24

P8 -0.14 1.08 -1.07 1.41

C4 -0.74 0.83 -1.62 0.34

TP8 0.11 0.89 -0.58 1.41

T8 -0.05 0.87 -0.87 1.18

P7 -0.55 0.42 -1.08 -0.14

P3 -1.34 0.37 -1.70 -0.93

CP3 -1.19 0.37 -1.64 -0.87

CPZ -1.50 0.36 -1.98 -1.17

CZ -1.51 0.82 -2.18 -0.45

FC4 -1.20 1.06 -1.75 0.38

FT8 0.11 0.85 -0.72 1.21

TP7 -0.33 0.66 -0.85 0.62

C3 -1.08 0.33 -1.47 -0.77

FCZ -1.50 0.79 -2.13 -0.43

FZ -1.26 1.11 -2.24 0.29

F4 -0.90 1.15 -1.64 0.82

F8 -0.04 0.84 -0.70 1.20

T7 -0.24 0.59 -0.66 0.62

FT7 -0.30 0.73 -0.96 0.73

FC3 -1.11 0.67 -1.60 -0.19

F3 -0.83 0.75 -1.65 0.07

FP2 -0.77 0.80 -1.53 0.33

F7 -0.39 0.49 -0.94 0.09

FP1 -0.39 0.61 -1.03 0.41

85

Table D16



O2 -0.47 0.82 -1.93 0.69

O1 -0.79 0.91 -2.23 0.70

OZ -0.78 0.96 -2.73 0.68

PZ -1.09 0.54 -2.02 -0.38

P4 -1.14 0.91 -2.38 0.18

CP4 -1.17 0.63 -1.98 -0.40

P8 -0.65 0.75 -1.54 0.43

C4 -1.03 0.55 -1.94 -0.45

TP8 -0.54 0.46 -1.11 0.22

T8 -0.50 0.55 -1.26 0.37

P7 -0.47 0.45 -1.12 0.14

P3 -1.20 1.21 -3.99 -0.25

CP3 -0.89 0.45 -1.66 -0.37

CPZ -1.28 0.63 -2.67 -0.74

CZ -1.15 0.50 -2.27 -0.67

FC4 -0.95 0.62 -1.72 0.06

FT8 -0.61 0.81 -1.84 0.38

TP7 -0.40 0.42 -1.36 -0.03

C3 -0.72 0.42 -1.43 0.03

FCZ -0.94 0.55 -1.83 -0.33

FZ -0.65 0.52 -1.30 0.05

F4 -0.59 0.89 -1.58 0.78

F8 -0.64 1.05 -2.46 0.40

T7 -0.32 0.57 -1.33 0.27

FT7 -0.18 0.51 -1.14 0.35

FC3 -0.53 0.42 -1.12 0.14

F3 -0.29 0.42 -1.06 0.37

FP2 -0.41 0.65 -1.54 0.12

F7 -0.11 0.51 -0.82 0.58

FP1 -0.14 0.56 -1.03 0.93

86

Table D17



O2 0.12 0.77 -0.99 1.14

O1 0.05 0.23 -0.30 0.37

OZ -0.04 0.35 -0.39 0.59

PZ -0.56 0.28 -0.85 -0.20

P4 -0.45 0.65 -1.59 0.42

CP4 -0.48 0.67 -1.27 0.60

P8 -0.30 0.65 -1.44 0.46

C4 -0.89 0.68 -1.63 -0.08

TP8 -0.38 0.56 -1.42 0.05

T8 -0.34 0.74 -1.51 0.51

P7 -0.15 0.47 -0.81 0.42

P3 -0.16 0.38 -0.58 0.50

CP3 -0.53 0.37 -1.12 -0.07

CPZ -0.87 0.53 -1.49 0.04

CZ -0.87 0.80 -2.17 -0.06

FC4 -0.81 1.48 -3.71 0.16

FT8 -0.41 0.64 -1.50 0.12

TP7 -0.14 0.45 -0.80 0.42

C3 -0.60 0.51 -1.51 0.00

FCZ -1.17 1.37 -3.84 0.11

FZ -0.93 1.99 -4.89 0.35

F4 -0.84 1.92 -4.69 0.32

F8 -0.27 0.75 -1.52 0.35

T7 -0.21 0.62 -1.19 0.68

FT7 -0.39 0.91 -1.72 0.72

FC3 -0.91 1.42 -3.65 0.34

F3 -0.71 1.48 -3.59 0.34

FP2 -0.62 1.58 -3.74 0.40

F7 -0.30 0.81 -1.27 0.69

FP1 -0.27 1.44 -3.15 0.72

87

Table D18



O2 -0.08 0.77 -1.08 0.76

O1 -0.27 0.85 -1.10 0.78

OZ 0.06 0.81 -0.85 1.09

PZ 0.15 0.87 -0.66 1.33

P4 0.31 0.73 -0.58 1.21

CP4 0.02 0.70 -0.63 0.67

P8 0.01 0.71 -1.02 0.49

C4 -0.03 0.65 -0.82 0.76

TP8 -0.01 0.62 -0.92 0.45

T8 -0.30 0.61 -1.06 0.21

P7 -0.40 0.48 -1.09 -0.08

P3 -0.33 1.13 -1.97 0.47

CP3 -0.21 0.87 -1.48 0.46

CPZ 0.13 0.98 -1.17 0.99

CZ -0.28 1.03 -1.77 0.58

FC4 -0.42 0.99 -1.61 0.58

FT8 -0.32 0.40 -0.78 0.07

TP7 -0.25 0.63 -1.09 0.31

C3 -0.35 1.10 -1.81 0.67

FCZ -0.57 1.18 -1.66 0.49

FZ -0.43 1.22 -1.67 0.72

F4 -0.27 0.51 -0.84 0.20

F8 -0.44 0.41 -0.88 0.10

T7 -0.72 1.08 -1.64 0.47

FT7 -0.59 1.15 -1.66 0.46

FC3 -0.46 1.42 -1.96 0.92

F3 -0.48 1.00 -1.57 0.38

FP2 -0.04 0.25 -0.42 0.11

F7 -0.70 1.10 -1.68 0.57

FP1 -0.39 0.55 -1.02 0.33

88

Table D19



O2 -0.31 0.66 -1.12 0.75

O1 -0.23 0.68 -1.16 0.67

OZ -0.54 0.66 -1.13 0.67

PZ -1.41 1.10 -3.44 -0.35

P4 -1.11 1.38 -3.15 0.87

CP4 -1.21 1.63 -4.32 0.49

P8 -0.92 0.79 -2.22 -0.09

C4 -1.12 1.75 -4.59 0.06

TP8 -0.68 0.90 -2.22 0.42

T8 -0.36 0.78 -1.65 0.46

P7 -0.39 0.52 -0.98 0.24

P3 -0.98 0.73 -2.22 -0.06

CP3 -0.98 1.06 -2.90 -0.14

CPZ -1.61 1.54 -4.48 -0.38

CZ -1.30 1.75 -4.61 0.04

FC4 -0.97 1.51 -3.97 0.12

FT8 -0.36 0.70 -1.67 0.31

TP7 -0.31 0.54 -1.00 0.22

C3 -0.90 1.14 -2.92 -0.04

FCZ -1.08 1.80 -4.49 0.86

FZ -0.70 1.12 -2.90 0.26

F4 -0.62 1.06 -2.35 0.49

F8 -0.51 0.68 -1.66 0.28

T7 -0.30 0.59 -1.37 0.34

FT7 -0.18 0.74 -1.62 0.35

FC3 -0.76 1.01 -2.47 0.31

F3 -0.23 0.49 -1.14 0.23

FP2 0.14 0.55 -0.52 1.08

F7 -0.13 0.89 -1.75 0.68

FP1 0.32 0.34 -0.10 0.72

89

Table D20

Descriptive Statistics for RMS Amplitudes of the Mismatch Negativity for Group 3 with Stimulus of -10 ms


O2 -0.20 0.73 -0.89 1.09

O1 -0.54 0.60 -1.34 0.25

OZ -0.63 0.80 -2.08 0.00

PZ -0.70 1.20 -1.93 1.43

P4 -0.40 0.97 -1.52 1.25

CP4 -0.54 0.48 -1.15 -0.04

P8 0.13 0.30 -0.25 0.47

C4 -0.19 0.64 -1.17 0.72

TP8 0.28 0.60 -0.47 1.12

T8 0.23 0.59 -0.48 1.01

P7 -0.48 0.36 -1.02 -0.07

P3 -0.75 0.78 -1.64 0.72

CP3 -0.74 0.56 -1.32 0.22

CPZ -0.73 1.01 -1.99 0.91

CZ -1.03 1.20 -2.99 0.31

FC4 -0.39 0.61 -1.04 0.37

FT8 0.45 0.69 -0.48 1.36

TP7 -0.41 0.42 -1.03 0.16

C3 -0.81 0.44 -1.30 -0.19

FCZ -0.72 0.73 -1.48 0.25

FZ -0.49 0.99 -1.46 1.07

F4 -0.09 0.57 -0.62 0.75

F8 0.45 0.61 -0.50 1.37

T7 -0.38 0.59 -1.15 0.41

FT7 -0.35 0.45 -1.01 0.04

FC3 -0.82 0.57 -1.38 0.15

F3 -0.35 0.90 -1.17 0.87

FP2 -0.12 0.41 -0.55 0.42

F7 -0.33 0.72 -1.04 0.72

FP1 -0.22 0.85 -0.93 1.38

90

Table D21



O2 -0.34 0.51 -1.35 0.09

O1 -0.27 0.42 -0.83 0.16

OZ -0.34 0.48 -1.23 0.23

PZ -1.21 1.54 -4.52 0.31

P4 -0.67 0.85 -2.52 0.08

CP4 -0.89 1.14 -3.50 0.08

P8 -0.40 0.67 -1.88 0.22

C4 -0.87 1.35 -4.00 0.13

TP8 -0.15 0.78 -1.87 0.76

T8 -0.26 0.71 -1.81 0.36

P7 -0.10 0.43 -0.72 0.42

P3 -0.69 0.67 -2.06 -0.04

CP3 -0.65 0.67 -1.67 0.25

CPZ -1.33 1.52 -4.68 0.29

CZ -1.08 1.48 -4.33 0.27

FC4 -0.84 1.32 -3.79 0.31

FT8 -0.13 0.76 -1.81 0.46

TP7 -0.13 0.44 -0.73 0.42

C3 -0.54 0.66 -1.68 0.26

FCZ -0.88 1.68 -4.58 0.46

FZ -0.52 1.23 -3.18 0.87

F4 -0.48 1.00 -2.58 0.91

F8 -0.18 0.78 -1.76 0.80

T7 -0.18 0.28 -0.57 0.18

FT7 -0.09 0.36 -0.63 0.34

FC3 -0.55 0.95 -1.95 0.45

F3 -0.23 0.73 -1.41 0.92

FP2 0.04 0.92 -0.88 1.67

F7 -0.06 0.35 -0.63 0.39

FP1 -0.13 0.76 -1.17 1.08

91

Table D22

Descriptive Statistics for RMS Amplitudes of the Mismatch Negativity for Group 3 with Stimulus of 10 ms


O2 -0.22 0.38 -0.64 0.33

O1 -0.13 0.64 -0.76 0.87

OZ -0.35 0.63 -1.09 0.54

PZ -1.12 0.92 -2.28 0.38

P4 -0.79 0.54 -1.85 -0.20

CP4 -0.91 0.61 -1.87 0.20

P8 -0.24 0.51 -0.62 0.66

C4 -1.15 0.42 -1.79 -0.55

TP8 -0.42 0.20 -0.67 -0.06

T8 -0.39 0.30 -0.80 -0.07

P7 -0.28 0.48 -0.89 0.55

P3 -0.64 0.93 -1.86 0.69

CP3 -1.02 0.60 -2.10 -0.24

CPZ -1.47 0.92 -3.02 -0.52

CZ -1.43 0.82 -2.60 -0.34

FC4 -1.16 0.66 -2.02 -0.18

FT8 -0.53 0.54 -1.35 0.09

TP7 -0.27 0.48 -0.87 0.55

C3 -1.09 0.64 -1.94 -0.35

FCZ -1.27 0.92 -2.29 0.23

FZ -1.26 0.99 -2.57 0.42

F4 -1.33 1.27 -3.81 0.05

F8 -0.40 0.37 -0.83 0.11

T7 -0.54 0.09 -0.63 -0.41

FT7 -0.47 0.81 -1.69 0.92

FC3 -1.07 0.99 -2.36 0.82

F3 -1.05 1.23 -2.31 0.81

FP2 -0.34 0.82 -1.65 0.84

F7 -0.77 0.63 -2.10 -0.17

FP1 -0.90 1.13 -2.50 0.55

92

Table D23



O2 -0.52 1.09 -2.93 0.46

O1 -0.50 0.81 -1.86 0.36

OZ -0.52 1.06 -2.67 0.63

PZ -1.07 0.97 -2.71 0.08

P4 -0.92 0.98 -2.99 0.01

CP4 -0.84 1.08 -2.37 0.63

P8 -0.56 0.65 -1.59 0.45

C4 -0.51 1.08 -2.29 0.90

TP8 -0.53 0.55 -1.34 0.19

T8 -0.25 0.84 -1.35 0.60

P7 -0.44 0.36 -1.08 0.03

P3 -0.70 0.77 -2.11 0.41

CP3 -0.53 0.66 -1.63 0.25

CPZ -0.93 1.16 -2.73 0.51

CZ -0.45 1.00 -1.62 0.80

FC4 -0.17 1.01 -1.80 0.93

FT8 -0.14 0.69 -1.38 0.88

TP7 -0.36 0.46 -1.05 0.35

C3 -0.28 0.75 -1.38 0.56

FCZ -0.13 0.95 -1.30 1.06

FZ 0.06 0.92 -1.03 1.46

F4 -0.02 0.94 -1.50 1.52

F8 -0.10 0.76 -1.37 1.18

T7 0.09 0.71 -0.45 1.73

FT7 0.19 0.56 -0.37 1.44

FC3 -0.10 0.88 -1.55 0.85

F3 0.30 0.80 -0.71 1.60

FP2 -0.06 0.99 -1.33 1.80

F7 0.26 0.63 -0.36 1.68

FP1 0.29 1.07 -0.61 2.30

93

Table D24



O2 -0.58 0.86 -1.88 0.60

O1 -0.62 1.07 -2.49 0.45

OZ -0.59 1.03 -2.52 0.25

PZ -1.13 1.63 -3.13 1.50

P4 -0.70 1.35 -2.15 1.50

CP4 -0.94 1.12 -2.16 0.92

P8 -0.63 1.07 -2.38 0.25

C4 -0.83 1.10 -1.73 1.15

TP8 -0.56 0.84 -2.12 0.35

T8 -0.61 0.81 -1.96 0.37

P7 -0.59 1.40 -2.19 1.68

P3 -0.78 1.68 -2.50 2.13

CP3 -0.77 1.65 -2.41 2.25

CPZ -0.99 1.55 -2.93 1.59

CZ -1.11 1.28 -2.87 0.88

FC4 -0.80 0.89 -1.61 0.37

FT8 -0.75 0.95 -2.00 0.46

TP7 -0.53 1.31 -1.67 1.71

C3 -0.87 1.23 -2.05 1.22

FCZ -1.18 1.12 -2.43 0.42

FZ -0.80 0.92 -2.10 0.34

F4 -1.11 0.87 -2.27 -0.07

F8 -0.80 0.93 -2.02 0.42

T7 -0.45 1.03 -1.49 1.09

FT7 -0.31 0.80 -1.27 0.64

FC3 -0.78 1.05 -1.97 0.89

F3 -0.73 0.94 -1.68 0.24

FP2 -0.61 0.95 -1.69 0.54

F7 -0.36 0.87 -1.39 0.69

FP1 -0.53 1.04 -1.63 0.94

Documents

NEUROPHYSIOLOGIC AND BEHAVIORAL MEASURES OF PHONETIC